The problem with electricity generated from wind turbines is, the power can fluctuate. Xcel Energy says it's got a way to even out the flow - an 80-ton battery the size of two semi-trailers. The Minneapolis-based utility said Thursday that it will begin testing a sodium-sulfur battery being used in Japan to even out the flow of electricity between windy days and nonwindy days. Xcel plans to put 20 50-kilowatt batteries in Luverne, Minn., about 30 miles east of Sioux Falls, S.D., this spring and connect them to an 11-megawatt wind farm owned by Minwind Energy. The batteries are expected to go online in October.

The largest wind turbine manufactured in the United States is running into some technical difficulty. Clipper Windpower Inc.'s 2.5-MW Liberty wind turbines at the 20-MW Steel Winds facility in Lackawanna, N.Y., are malfunctioning due to faulty gear sets. "At first, we were receiving great performance from the turbines," said Michael Alvarez, executive vice president and COO of UPC Wind Partners LLC, which co-owns the facility with BQ Energy LLC. "Over the summer, a gear-timing issue in the drive train's secondary stage was detected in some of Clipper Windpower's Liberty wind turbines at the Steel Winds site. The cause was found to be a supplier quality deficiency in the drive train attributable to the suppliers' manufacturing process. As part of Clipper's warranty, upgraded drive trains will be installed into all eight turbines at the Steel Winds site. Currently, two turbines are in operation."

It's back to the '70s for the south metro, as a new generation of major powerlines is being proposed for rural land -- and activists and farmers begin to meet. ...The companies are seeking state approval for a cluster of major lines. Two of them -- 345-kilovolt lines with towers as high as 150 feet, one stretching 230 miles west to South Dakota and the other 150 miles southward to Wisconsin -- would cross Dakota County. No specific pathway has yet been laid down, but the general outlines of the corridors -- mostly 10 to 12 miles wide -- are clear. Points of controversy are expected to include whether the lines are needed, whether they pose health risks and how much landowners should be paid.

"I currently have, in Minnesota, 23,000 megawatts of interconnection requests for wind," says Moeller, who oversees new connections for MISO. Another 23,000 megawatts of future wind power in North Dakota, South Dakota, Iowa and Wisconsin also is in line. In comparison, the entire Twin Cities metropolitan area typically draws about 6,000 megawatts of electricity out of the transmission system. While some have been on record for years, a sudden barrage of requests -- about 22,000 megawatts' worth -- has burst into MISO since Sept. 10. Minnesota's new renewable energy law, probably triggered some.

While it is pursuing wind power as a renewable resource -- most recently with a large deal last week -- that source is strictly supplemental, SMMPA spokesman Dan Hayes says. Wind-generated power is available when the wind blows, so it is not always online to ship. SMMPA needs to have enough power available 24/7 to supply its 18 city-owned utility companies and their customers. ...But there are other possibilities for baseline electricity, and SMMPA's chief operating officer, Dave Geschwind, says agency managers now are evaluating them more closely.

MINNEAPOLIS (AP) - A group of utilities in Iowa, Minnesota and the Dakotas plan to spend $200 million on a project in Iowa that would store energy generated by wind turbines. The Iowa Stored Energy Park would essentially act as a "battery" for wind energy, said Bob Haub, executive director of the Iowa Association of Municipal Utilities. Wind farms in Iowa, Minnesota and the Dakotas would ship energy over the power grid to the storage park near Des Moines. Xcel Energy and the federal government are experimenting with ways to "store" wind power in the form of hydrogen, but the Iowa project would employ a far simpler strategy that would include the following steps: